Improvement in burglar-alarms



I. B.' WO'OIDRUFF.

I BURGLAR-ALARM. No. 193,390. Patented July 24,1877.

NPETERS, PHOTO LITHDGRAPHER WASHINGTON D C Grrron ISAAC B. WOODRUFF, OF WINSTED, CONNECTICUT.

IMPROVEMENT IN BURGLAR-ALA RMS,

Specification forming part of Letters Patent No. 193,390, dated July 24,1877 application filed June 20, 1877.

To all whom it may concern Be it known that I, ISAAC B. WOODRUFF, of Winsted, in the county of Litchfield and State of Connecticut, have invented a certain new and useful Improvement in a Portable, Attachable, and Detachable Burglar- Alarm for Door-Knobs and the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, making a part of this specification, in which- Figure 1 represents a side view of my invention, showing the bell in section. Fig. 2 is a section on the linear a: of Fig. 1, showing the escapement mechanism.

My invention relates to a portable, cheap, and efficient burglar-alarm, such as any one traveling can take along with him'into his room, and on retiring at night, or at any time, attach to the door-knob in such a manner that the instant the knob is taken hold of and turned in either direction the alarm will be given and it consists in the arrangement and combination of an alarm-bell escapement movement, provided with a weighted pendulum and a clamping device, whereby the alarm movement is clasped to the door-knob and wound up by turning the bell, when it is in readiness to give the alarm by the slightest turning ofthe knob on either side.

To enable others to make and use my invention, I will describe it more in detail, referring to the drawings and the letters thereon,

The alarm movement may be the same, or constructed in a similar manner to those used in alarm-clocks-the bell-hammer operated'by an ordinary verge-escapement, the same being provided with a short-weighted pendulum, A, hung on pivots, so as to move easily in either direction, when the position of the device is changed. The top of the pendulum-bar a is brought to nearly an oval-shaped point, on which the wire b, forming the handle of the bell-hammer, rests. When the alarm is set the alarm-bell B is attached to stem of the winding-arbor C, so that the alarm is wound up by turning the bell B, thereby dispensing with a key, and is always in readiness for use. The bell, being placed over the alarm mechanism, protects it from harm incarrying.

To the inside of the movement is secured a spring clasp or clamp, D, the same being so formed with a slot, 01, leaving prongs to straddle the stem of the door-knob E, and a hinged stirrup, F, by which it can be almost instantly secured firmly to any ordinary size door-knob, held in position, wound up by the bell B, and ready at any moment for use.

I am well aware that burglar-alarm bells and various devices have been attached to doors in such positions that, by connecting bars and levers, they have been operated by a pin or cam on the shank of the door-knob by turning the knob; and I do not claim any such device, as they are not designed to be portable or detachable to be carried abroad, when traveling, or changed at any time from one door to another but What I claim as my invention isl. A burglar-alarm provided with the pendulum A, as constructed and arranged, in combination with the liberating-wire b, forming a portion of the bell-hammer handle, op-

crating substantially in the manner as and for the purpose herein set forth.

2. The forked clamp D, to attach to a doorknob, E, to hold the alarm mechanism securely in position by the clasp F, substantially as herein shown and described.

In testimony whereof I have subscribed my name to the above specification for improvement in a portable, attachable, and detachable burglar-alarm for door-knobs.

ISAAC B. WOODRUFF. 

